Residents as far north as Minneapolis are experiencing heat indexes of 115°F for the third day in a row.

Weather Defender basemap with Heat Index Contours enabled

The rest of the country is experiencing significant above-average heat:

Remember that extreme temperatures are the #1 weather killer, more than tornadoes, hurricanes and lightning combined. If you must be outside, look for shade and avoid unnecessary physical exertion during peak heat hours (noon-5PM). Infants and elderly are especially at risk during extreme heat, and should be monitored closely. Finally, drinking lots of water (16-32oz per hour) is a must to avoid dehydration.

Red: 110°F to 120°F - Danger: heat cramps, and heat exhaustion are likely; heat stroke is probable with continued activity

Pink: 120°F or higher - Extreme danger: heat stroke is imminent

This is critical information for anyone participating in summer-time activities: sports, camping, hiking, etc. Even keeping tabs on elderly friends and family members, especially at risk from heat-related illnesses.

The Heat Index layers can be found under the Surface Weather category in the Layer Browser.